daniel.brown@LIGO.ORG - posted 23:00, Saturday 24 November 2018 - last comment - 09:22, Sunday 25 November 2018(45477)
Crystal chiller down again
Crystal chiller has just gone down again. Checked the fill tube and the water is below the minimum mark like yesterday.
Just saw Georgia Mansell's email from late last night about the chiller tripping again.
Just talked with Peter King. He and I will meet in the Chiller Room at 8:30 this morning to adjust chiller flows in hopes of curing these trips.
It appears that there are two issues.
First, it appears that the sensors cannot meter flows as low as we would like to maintain (1.2 lpm through the FrontEnd, 70-W, and High Power Shutter circuits).
Second, there is a small leak that the back of the chiller that was there since the flow throttling valve was installed about two weeks ago.
PeterK and RickS
We filled the Crystal Chiller (about 500 ml) and started it. The flow displayed on the chiller controller was only about 13 lpm. We opened the throttle valve at the chiller output (fourth attached photo) to restore it to about 18 lpm (second attached photo).
Then, we adjusted the bypass valve on the wall (third attached photo) to give us about 40 PSI on the supply side (20 PSI on the return side) (first attached photo).
This results in about 1.7, 2.0, 1.7 (Front End, 70-W, HP shutter) lpm flows through the three Crystal Chiller circuits.
We also tightened the LXT (PVC) female adapter (to 3/4" NPT male street el) which appears to have stopped the leak at the chiller.
These flows may be larger than we will want for O3, but the system will hopefully run more reliably at these flow levels as we investigate options for reducing flows if required to reduce water-flow-induced noise on the PSL table.